What are these and how do I control them

[Orkine]

I have some pest identification and pest control questions.

There are what I assume to be 3 different things.

First:  Some bug is eating notches in my lychee.  I assumed it is a weevil of some sort but have never spotted it.
See images below



Next on lychee and longan, there is this ?I don't know what it is?  that is on the underside of a number of leaves.  It does not appear to be moving and may be the case of a bud long gone or some stage in the life cycle where it is not active.  Can you id this and how do I treat control this?




Lastly, there are these neat rows of what I assume are scales along the ribs of several leafs, see images below.  Other than scraping them off, is there anything I should be doing?

[sidney]

Sri lanka beetle, feed at night.

[MangoCountry]

The third set of pics are scales. Had same thing on my lemon zest mango. Tended by ants. Only on 2 leaves so I cut the off. Been fine since. First pics are that weevil. Look for a whitish beetle. Easy to catch and kill. They love mango and lychee. I go out at night with a flashlight and flick them into a cup filled with dish soap and water.

[Saltee]

First pic looks like leaf notcher weevils, they attack my graham mango tree and that tree only for some reason. I have a nam doc mai about 15 feet away that they do not bother.

Scale could be the problem too, which only affects my NDM and not the graham. These bugs seem to like the taste of some and dislike others

I bought some bayer systemic insecticide, it killed off all the scale but only slowed the weevils. It got rid  of the leaf hoppers as well. It’s weak compared to the strengths of insecticide you can order off eBay with the same ingredient but it worked for me

[achetadomestica]

Picture one looks like Sri Lankan Weevil
They are active at night and easy to see. I tried allot of
things to control them and finally figured out this
https://www.amazon.com/dp/B003IMIPF4/ref=psdc_3737951_t1_B00C4Y286O
I use 1/2 oz. per gallon of water and drench leaves and trunks of tree.
The weevil's larvae hatch and feed on the roots of the tree so after treatment
a infestation  may reoccur in 30 days or so. I check my trees at night with a flashlight.
 

[Saltee]

How do you tell the difference between leaf notchers and Sri Lanka’s? They look identical

[zands]

Sri lanka beetle, feed at night.

Looks like to me!  Orkine should go out at night with a flash light and take a look.  Though heavy rain today might have washed then down to the ground for a day or too.

If you see these critters at night you can spread a tarp. Shake them off the tree, then gather up the tarp and stomp on them. Or some kerosene aka diesel fuel from your local gas station at the low point in the tarp will kill them.

[achetadomestica]

Sri lanka beetle, feed at night.

Looks like to me!  Orkine should go out at night with a flash light and take a look.  Though heavy rain today might have washed then down to the ground for a day or too.

If you see these critters at night you can spread a tarp. Shake them off the tree, then gather up the tarp and stomp on them. Or some kerosene aka diesel fuel from your local gas station at the low point in the tarp will kill them.

Unfortunately picking off the ones you see will not rid you of them. They hatch and live underground for their larval
stage and continually infest the tree. It drove me crazy and some people say it's just an eyesore but they were eating half the
leaves off. There is no way this is beneficial to your tree. This is the best solution I have seen
https://www.amazon.com/dp/B003IMIPF4/ref=psdc_3737951_t1_B00C4Y286O